Valve gear



H. WIEGAND VALVE GEAR April 5, 1938.

File'd April 13, 1957 INVENTOR` fmf @ligand ATTORNEY www@ z 0 w 352W mm2WW Q MWA; luv

Patented Apr. i, 1938 UNITED STATES VALVE GEAR Hellmuth f Wiegand,Berlin-Lichtenrade, Germany, assigner to Willy Salge & Co., TechnischeGesellschaft, Berlin, Germany Application April 13, 1937, Serial No.136,529 In Germany March 26, 1936 4 Claims.

The present invention relates to mechanism for actuating valves of thepoppet type in reciprocating engines, particularly those using highlysuperheated and high pressure steam. The

5 usual gear for actuating such valves includes some means to bias orload the valves or some connected element so the valves are urgedresiliently toward closed position. In prior gears of the general typeto which the present invention re lates. there was either a separateloading or biassing member or element for each valve, or there was asingle member of this kind for the two valves at each end of thecylinder, such member in either case being a spring or a pressurecylinder arranged coaxially with the valve. There were in the prior artvalve-closing means common to the two valves at the same end of thecylinder but these means lie inside of the valve chest and are in allcases exposed to the steam ,0 temperatures. They further have thedisadvantage that the closing force is not adjustable. In

addition their relatively great length, and the diiiculty of access wereserious drawbacks. This was particularly true in those cases where thefour valves were arranged in alinement.

In the case of the present invention, two juxtaposed valves have commonclosing means, Whose force is exerted on both valves at the same time bymeans of rods and levers.

As compared with prior devices of this sort the construction hereinproposed has the following advantages:

parts are all readily accessible.

Inspection and adjustment are very easy.

The undesirable effects of heat radiation and conduction on the valveclosing members are greatly reduced.

The valve rods are simple and the valve closing means are incorporatedin the valve actuating gear.

be given the large dimensions required in prior constructions where theyserved to accommodate the valve closing member, which was a spring or apressure cylinder.

In the drawing two illustrative examples of the invention are shown.Fig. 1 shows an arrangement of such a gear comprising a spring, the twovalves being double-seated and opening in a direction toward each other,one of them being the inlet valve and the other the exhaust valve. Thespring\.tending to close the valves in this case is arranged around thepush rod which acts from the outside to open one of the valves. Fig. 2is a lateral elevation of Fig. 1 viewed from the right.

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The valve rods therefore do not need toA Fig. 3 shows an arrangement ofa pressure cylinder used as the closing means for two valves, whichinfthis case open in a direction away from each other. Fig. 4 is thecorresponding lateral elevation vof Fig. 3 viewed from the right. 5

According to Figs. 1 and 2 the cam shaft I with its cams 2 actuatesvalve 3 by means of the lever 4 and actuates valve 5 by means of thelever 6, the push rod 1 and the lever 8. The two levers 4 and Ii havethe common fulcrum 10 30. The lever 4 has an extension which ispivotally connected to the yoke 9, the end of the yoke furnishing one ofthe abutments for the spring I0. The opposite abutment for this springis furnished by the washer II which is held ad- 15 justably on the pushrod I by means of the nut I2. The spring IIJ exerts its resilientclosing power on the alternatelyactuated valves 3 yand 5 through thewasher II and yoke 8 and the valve rods and gear. 20

Figs. 3 and 4 show an arrangement of such a gear utilizing a pressurecylinder as the resilient closing force. In this case the cam shaft I3with its cams I4 acts on the valve I5 by means of the lever I6 and onthe valve I1 by means of the lever I8, push rod I9 and lever 20, thelevers being kmounted on lthe common fulcrum 3|. The lower end of thepush rod I9 is given the form o1' a pressure cylinder to which aresecured two tension arms 2| whose 30 ends are pivotally connected to thelever I8; In the pressure cylinder there is mounted reciprocably thepiston 22 whose rod 23 is pivotally connected to the lever I6. Thepressure iiuid is delivered to the cylinder by means of the connec- 35tion 24.

What I claim is:

1. Valve gearfor reciprocating engines having poppet-type valvesarranged in a valve chest in axially alined pairs, each pair includingan 40 inlet valve and an exhaust valve, the two -valves opening inopposite directions; two valve actuating members, a Atrain of elementsextending from one of the valves to one of the actuating members, asecond train of elements extending 45 from the other valve to theotheractuating member, said actuating members being operative through saidtrains of elements to raise the valves alternately from their seats, anda common valveclosing element engaging one elementI of each 50 train andresiliently urging the two valves toward their seats, the seating forceof said closing element on one valve increasing as the other valve isopened, said trains and valve closing element lying wholly outside ofthe valve chest. 55

' 2*. Valve'gear in accordance with claim 1, the valves being arrangedto open in a direction to- Ward each other.

3. Valve gear in accordance with claim 1, the

5A .valves being arranged to open in a direction away from each other.

4. Valve gear for reciprocating engines havin'g poppet-type valvesarranged in a valve chest in axially alined pairs, each pair includingan 10 inlet valve and an exhaust valve, said gear for `-each pairofvalves comprising a stem for each member, all of the gear between thetwo stems lying Wholly outside of the valve chest.

HELLMUTH WIEGAND.

